Field of the Invention
The present technology is a lighting system that relies on thermoelectricity for power. More specifically, it is a flashlight that is powered from body heat.
Description of the Related Art
Portable light sources such as head lamps and flashlights rely on a power source that is independent of the grid. Often, these light sources are used irregularly, are needed in emergency situations and if powered by batteries, tend to not work when needed as the batteries have died. Even if rechargeable batteries are used, charged batteries must be available when those powering the light source die. As a result, alternative designs have been developed that provide a ready power source.
Hand crank dynamos have been used both in lights and in portable cell phone rechargers. One such design, called the Sidewinder, is voltage regulated to keep the voltage reasonably stable even if the generator speed varies. This Sidewinder also includes a miniature flashlight capability. There is a white Light Emitting Diode (LED) on the top of the unit, and when the hand crank is turned, the generated power can either be used to recharge a cell phone or to turn on the light. A built in capacitor stores some charge so the light will continue to glow for a couple of minutes after a thirty second charge. The Preparedness Center (Ukiah, Calif.) markets a solar powered, hand crank powered flashlight and AM/FM radio. Safety Buddy, Inc. (Irvine, Calif.) markets a hand crank AM/FM dynamo radio with a lantern light. Unfortunately, the hand crank devices tend to have a short life span, are difficult to use in situations where the user is trying to focus the light on a specific location, for example when trying to unlock a door and they cannot be hands free.
It is known that thermoelectric generators such as Peltier modules, working on the Seebeck Principle, can be used to produce electric current. The Seebeck Effect states that electric current is produced when two dissimilar metals (such as bismuth and telluride) are joined, and one side of their junction is cooled while the other is heated. As in U.S. Pat. No. 7,626,114 a thermoelectric power supply converts thermal energy into a high power output with voltages in the Volt-range for powering a microelectronic device and comprises an in-plane thermoelectric generator, a cross-plane thermoelectric generator, an initial energy management assembly, a voltage converter and a final energy management assembly.
There exists a need to provide a portable light source that can be powered thermoelectrically, using thermoelectric generators. This would remove the requirement for batteries, toxic chemicals or kinetic energy and would provide a flashlight that does not create any noise or vibrations. An additional goal would be to provide a hands free flashlight. The power source could similarly be employed for other portable devices having power requirements that are the same or lower than a flashlight.